Comparison of Bone Scan with Bone Mineral Densitometry as Assessment of Response to Hormonal Therapy in Metastatic Prostatic Cancer

Jeung, Hee Jong; Park, Kwang Sung; Park, Yang Il; Song, Ho Cheun

Abstract

Patient with osseous metastatic prostatic cancer can clinically be detected by bone scanning, which usually is sensitive and qualitative but is not specific and quantitative. For quantitative evaluation of skeletal lesions, we measured bone mineral density (BMD) in whole body, total spine and lumbar spine. All patients also were assessed with bone radiography, radionuclide bone scan, prostate specific antigen (PSA), and prostatic acid phosphatase (PAP). We compared mainly bone scan and BMD in monitoring tumor response between before hormonal treatment and 6 month after hormonal treatment. Fifteen patients with stage D2 prostate cancer and 25 controls were entered in this study. Of 8 patients whose scan showed response in 12 patients with metastatic lumbar spine lesion, they had either 7 responded or 1 unchanged BMD level in the lumbar spine. Of 9 patients whose scan showed response in 15 patients with metastatic total spine lesion, they had either 6 responded or 3 unchanged BMD level in the total spine. The alterations of BMD levels in total spine and lumbar spine closely correlated with the therapeutic responses assessed by the National Prostatic Cancer Project Criteria of bone scintigraphy in patients with prostatic cancer (spine: r=0.04, p<0.05; lumbar: r=0.1, p<0.05). In contrast, BMD changes in whole body (response rate: 20.0%, P<0.05) was less than that in total spin (response rate: 53.3%, P<0.01) and lumbar spine (response rate: 58.3%, P<0.01). In conclusion, when compare BMD to the hot spot region in bone scan, BMD may be helpful to the urologist for the accuracy of the staging and evaluation of the treatment response to androgen deprivation therapy in metastatic prostate cancer.